Notes Receivable - Interest Income and Payment Received (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income	$ 5,685	$ 7,304	$ 11,769
Payment received relating to notes receivables	844	2,985	13,211
Notes Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income	5,500	6,200	10,200
Payment received relating to notes receivables	6,400	8,800	$ 11,300
Bonds A and B Series [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accrued interest receivable	$ 41,000	$ 40,900